So in my adventures fixing up various vintage quantel products i am coming across a particular IC that always seems to fail. From what i understand the failure also happens in other equipment so it's not like quantel were using this out of spec. The particular ic in question is just known to 'go bad'
In this case the IC is a ST Micro STV1601 and it's partner the STV1602, they are a SDI (serial digital video) serialiser and de-serialiser pair and were manufactured in the mid 90s to sometime in the early 00s. The 1601 takes 10 bit parallel data and converts it into serial digital video and the 1602 does it the other way around. Quantel used them for SDI video input/output on their broadcast equipment.
I understand they were originally manufactured by Sony as the SBX160x and these were even more notorious for going bad but at some date the Sony parts seem to disappear and be replaced by ST Micro branded parts and the device name changed to STV160x. It also looks like manufacturing switched from Japan to France.
Some people have said it's heat related, but i have just been through some of my spare new-old-stock quantel boards that use this IC and all of the STV1601 devices seem to be dead even though they don't appear to have been used, so it could even be an age thing. Interestingly the 1601 part seems to be much worse than the 1602 and quantel in later versions of their products switched from using the 1601 to a entirely different Cypress part but retained the 1602 indicating the 1601 is particularly troublesome.
So out of curiosity i am just asking what are some of the causes in systemic failures in a particular ic like this, why one would be worse than the other and how it can continue to be manufactured with what is clearly some kind of flaw? heat, age, poor design, poor manufacturing?
The STV160x devices are a ceramic PGA device as pictured below.